A former wastewater spray field in Lake City is now a 121-acre wetlands project that is part of a $100 million statewide springs restoration initiative.
The project has four primary goals, said Lindsey Garland, communications coordinator at the Suwannee River Water Management District.
“The projects focus on ensuring adequate and sustainable water supply, improving and maintaining good water quality, restoring and protecting natural systems, and improving flood protection,” Garland said.
Four of Florida's five water management districts have springs.
In Lake City, the district is already seeing results.
The wetlands construction was part of the $4.2 million first phase of the ongoing Ichetucknee Springs Water Quality and Quantity Enhancement project. It began operating in late 2017.
Kristine Eskelin, the district’s senior project manager, said plants in the wetlands are used to reduce high nitrogen levels, which are caused by human and animal waste as well as fertilizer runoff and produce algae in the springs. Eskelin said the wetlands removed 30,000 pounds of nitrogen in the first year alone.
About 2 million gallons of water a day comes from two wastewater plants that serve Lake City. The water treated at the plant is stored in its reservoir and excess is pumped into the wetlands.
“Seventy-five percent of the wastewater that came out of” the Lake City Waste Water Plant “was recharged by the plants and improved the springs,” Eskelin said.
The wetland is composed of nine cells. Upstream cells, which are marked by algae and duckweed, are closest to where treated wastewater is released. Two natural recharge zones infiltrate the Ichetucknee Trace at a rate of about 1.3 million gallons a day.
While the project carefully considered which plants to add while constructing the wetlands, many new species of plants and animals have appeared since construction, said Tyler Todd, the treatment plant’s lead operator.
Some, like the fist-sized apple snails that “take over” the area are relatively harmless, Todd said, while others, like the Carolina Willow trees that grow on the edge of the cells, must be removed.
Oxygen from the plants allows bacteria to grow and accounts for some of the nitrogen removal.
“It kind of runs itself,” Todd said. “Nature does most of it. We just kind of control it a little bit.”
Pressure valves at each cell divert water to others. Meters take elevation readings at the bottom of each cell and can help control one from spilling into another.
By reducing the nitrogen levels through the recharge here, Eskelin said, “We hope that will ultimately be reflected in the Ichetucknee Springs and rivers and the Santa Fe River.”
Depending on groundwater levels and where a recharge area is, she said, it can take from days to years to see results.
Contracts are being signed for the $1.2 million second phase of the project, Eskelin said. It will add a recharge well and gravity flow capabilities, which Todd said will reduce the facility’s operating cost, with hopes of tripling the amount of water that can be treated and recharged.
The second phase is expected to take about 20 months through construction and up to three years with monitoring and recording changes.
Eleven other projects from the same funding are still in the works for Lake City, Garland said.
She said they would provide residents with access to water and recreation as well as habitats for birds and aquatic life.
“One example is a project that will replace 67 septic tanks in the city of Greenville and connect the houses to a central sewer system,” Garland said.
Septic tanks are a known cause of worsening water quality in Florida, as their failures lead to increased nitrogen levels.
“This project will reduce nutrients by 286 pounds per year,” Garland said. “Decreasing the nutrients that is entering the aquifer means less nutrients that will enter the springs and rivers.”